The invention describes a new mammalian composite promoter/enhancer expression element.
The cytomegalovirus immediate/early enhancer/promoter element (Pcmv) is currently the strongest known mammalian promoter element, and as such puts an upper limit on transgene expression in in vitro and in vivo systems.
It would therefore be desirable to be able to include a further element in a vector that allows increased transgene expression to be attained.